Sound Signal Processing Apparatus and Degree of Speech Computation Method

1. A processor-implemented sound signal processing apparatus comprising: a sound computation mechanism configured to compute and output an indicia of a degree of vocally generated sound of a sound signal input thereto, said sound signal including a vocally generated sound and ambient sound; and a voice processor configured to characterize the input sound signal based on the indicia of a degree of vocally generated sound output by the sound computation mechanism, wherein the sound computation mechanism is configured to compute the indicia of a degree of vocally generated sound based on features in a wavelength direction of a waveform of the input sound signal; said sound computation mechanism including a degree of speech computation mechanism comprising: a half-wavelength increase and decrease repetition rate computation mechanism configured to compute an increase and a decrease in a repetition rate of half wavelengths of a waveform of the sound signal; a zero-cross rate computation mechanism configured to compute a rate of zero crossings of half wavelengths of the waveform of the sound signal; and a degree of vocally generated sound output mechanism configured to output the indicia of a degree of vocally generated sound on the basis of an output from the half-wavelength increase and decrease repetition rate computation mechanism and an output from the zero-cross rate computation mechanism.

2. The apparatus of claim 1 , wherein: said vocally generated sound is speech; and said voice processor is configured to characterize the input sound signal based on a degree of speech in said sound signal as determined by said sound computation mechanism.

3. The sound signal processing apparatus according to claim 2 , wherein the features in the wavelength direction are changes in a duration of a period of waveform of the sound signal.

4. The sound signal processing apparatus according to claim 2 , wherein the features in the wavelength direction are changes in a level direction of the waveform of the sound signal.

5. The sound signal processing apparatus according to claim 2 , wherein the degree of speech computation mechanism is configured to compute the degree of speech in units of frames sliced in predetermined time length units of the sound signal.

6. The sound signal processing apparatus according to claim 1 , wherein the half-wavelength increase and decrease repetition rate computation mechanism is configured to compute the increase and decrease repetition rate of the half wavelength of the waveform based on a rate of a portion of the waveform where an upward half-wavelength of the waveform of the sound signal changes so as to increase and decrease alternately or changes so as to decrease and increase alternately, and based on a rate of a portion where a downward half-wavelength of the waveform of the sound signal changes so as to increase and decrease alternately or changes so as to decrease and increase alternately.

7. The sound signal processing apparatus according to claim 1 , wherein the half-wavelength increase and decrease repetition rate computation mechanism includes a first output value adjustment mechanism configured to adjust the repetition rate of the half wavelengths produced by the half-wavelength increase and decrease repetition rate computation mechanism, the zero-cross rate computation mechanism includes a second output value adjustment mechanism configured to adjust the rate of zero-crossings produced by said zero-cross rate computation mechanism, and the first and second output value adjustment mechanisms are configured to adjust and provide respective output values to the sound output mechanism.

8. The sound signal processing apparatus according to claim 2 , further comprising: a band dividing mechanism configured to divide the sound signal into a plurality of frequency bands, wherein the sound computation mechanism is configured to compute the indicia of a degree of vocally generated sound for each band, and the voice processor is configured to process each band on the basis of the computed degree of vocally generated sound of each band.

9. A method for computing an indicia of a degree of vocally generated sound, comprising: slicing a waveform of an input sound signal in units of frames of a predetermined length; computing and outputting the indicia of a degree of vocally generated sound of a sound signal input thereto, said sound signal including a vocally generated sound and ambient sound; and characterizing the input sound signal based on the indicia of a degree of vocally generated sound; wherein said computing and outputting includes: computing the indicia of a degree of vocally generated sound based on features in a wavelength direction of a waveform of the input sound signal, computing an increase and a decrease in a repetition rate of half wavelengths of the waveform sliced in the slicing, computing a rate of zero crossings of half wavelengths of the waveform sliced in the slicing, and determining and outputting the indicia of a degree of vocally generated sound on the basis of an output from the computed increase and decrease in the repetition rate and the computed rate of zero crossings.

10. The method according of claim 9 , wherein: in the computing an increase and decrease in the repetition rate, the increase and decrease repetition rate of the half wavelength is computed on the basis of a rate of a portion of the signal where an upward half-wavelength of the waveform changes so as to increase and decrease alternately or changes so as to decrease and increase alternately, and on the basis of the rate of the portion where a downward half-wavelength of the waveform changes so as to increase and decrease alternately or changes so as to decrease and increase alternately.

11. The method of claim 9 , wherein: the computing an increase and decrease in the repetition rate includes adjusting the repetition rate of half wavelengths, and the computing a rate of zero crossings includes adjusting the rate of zero-crossings.

12. The method of claim 9 , further comprising: dividing the sound signal into a plurality of frequency bands, and computing the indicia of a degree of vocally generated sound for each band.

13. A computer readable storage medium having computer readable instructions that when executed by a processor cause the processor to perform a method comprising: slicing a waveform of an input sound signal in units of frames of a predetermined length; computing and outputting the indicia of a degree of vocally generated sound of a sound signal input thereto, said sound signal including a vocally generated sound and ambient sound; and characterizing the input sound signal based on the indicia of degree of vocally generated sound; wherein said computing and outputting includes: computing the indicia of a degree of vocally generated sound based on features in a wavelength direction of a waveform of the input sound signal, computing an increase and a decrease in a repetition rate of half wavelengths of the waveform sliced in the slicing, computing a rate of zero crossings of half wavelengths of the waveform sliced in the slicing, and determining and outputting the indicia of a degree of vocally generated sound on the basis of an output from the computed increase and decrease in the repetition rate and the computed rate of zero crossings.

14. The computer readable storage medium of claim 13 , wherein: in the computing an increase and decrease in the repetition rate, the increase and decrease repetition rate of the half wavelength is computed on the basis of a rate of a portion of the signal where an upward half-wavelength of the waveform changes so as to increase and decrease alternately or changes so as to decrease and increase alternately, and on the basis of the rate of the portion where a downward half-wavelength of the waveform changes so as to increase and decrease alternately or changes so as to decrease and increase alternately.

15. The computer readable storage medium of claim 13 , wherein: the computing an increase and decrease in the repetition rate includes adjusting the repetition rate of half wavelengths, and the computing a rate of zero crossings includes adjusting the rate of zero-crossings.

16. The computer readable storage medium claim 13 , wherein the method further comprising: dividing the sound signal into a plurality of frequency bands, and computing the indicia of a degree of vocally generated sound for each band.

17. A processor-implemented sound signal processing apparatus comprising: means for slicing a waveform of an input sound signal in units of frames of a predetermined length; means for computing and outputting an indicia of a degree of vocally generated sound of a sound signal input thereto from the means for slicing, said sound signal including a vocally generated sound and ambient sound; and means for characterizing the input sound signal based on the indicia of a degree of vocally generated sound, wherein said means for computing includes: means for calculating the indicia of a degree of vocally generated sound based on features in a wavelength direction of a waveform of the input sound signal, and a degree of speech computing means comprising: a half-wavelength increase and decrease repetition rate computing means for computing an increase and a decrease in a repetition rate of half wavelengths of a waveform of the sound signal; a zero-cross rate computing means for computing a rate of zero crossings of half wavelengths of the waveform of the sound signal; and a degree of vocally generated sound outputting means for outputting the indicia of a degree of vocally generated sound on the basis of an output from the half-wavelength increase and decrease repetition rate computing means and an output from the zero-cross rate computing means.